(1) Field of the Invention
The present invention relates to a tractor having improvements in the wheel supporting mechanisms, the wheel drive mechanisms and the axle case mechanisms so as to permit the vehicle body height from the ground and the rut distance to be adjusted.
(2) Description of the Prior Art
In order to apply a tractor to various kinds of works, the tractor should be constructed such that its body height from the ground and rut distance can be adjusted.
Generally, the vehicle body height from the ground may be adjusted by changing the wheels to other wheels having different diameters or by arranging such that the wheels may be attached selectively at different positions of the vehicle body.
The rut distance may be adjusted by expanding and contracting the wheel axles.
If such mechanisms for adjusting the vehicle body height from the ground and the rut distance are disposed at the sides of the wheels to be driven, the whole structure becomes extremely complicated.
Besides, if a steering function is added to such mechanisms, the whole structure becomes further complicated.
In order to perform such adjustments of the vehicle body height from the ground and the rut distance, provision should be made to lift up the vehicle body in a stable manner.